Door stops, more particularly for smoke doors



United States Patent 3159,8594 DOOR STUPS, MQRE PARTKQULARLY FQR SMGKE DGQRS Roland Ernest Sent, 16 Molland Close, West Derby, Liverpool 12, England Filed Get. 16, 1962, Ser. No. 230,321 2 Qlaims. (Cl. 292-2ill) This invention relates to door stops and more particularly, although not exclusively, door stops for the socalled smoke doors of buildings.

Such doors are conventionally located across passageways, at the entrance to staircases, and in like locations in order that, in the event of fire, the rapid spreading of smoke and heated air can be prevented, or substantially retarded, thereby enabling passages and Stairways to remain safe for use as long as possible.

Smoke doors are usually of swing or other self-closing type, i.e., are adapted for spring-influenced or other biased movement towards closed position, but frequently, for convenience of movement and for ventilation purposes they are secured in an open position. For this purpose door stops are used which may be located in the floor, or wall, or other surface, or merely consist of wedge pieces slipped under the bottom of the door. In all forms they constitute a grave danger in the event of fire, as, if not removed or released, the smoke doors become useless for the purpose intended and lives, which might otherwise be saved, may be lost because of Stairways and the like quickly becoming impassable due to smoke and heat.

According to my invention, a door stop for a swing or other self-closing door broadly comprises a detent for holding the door in open position, electro-magnetically operable means for moving said detent to inoperative position, and means for positively holding the detent in such inoperative position until intentionally reset. The electromagnetic means, for example, a solenoid with an armature or plunger, is adapted for remote operation, for example, by being connected in the electrical circuit of a fire alarm or other warning system whereby, in the event of an alarm being initiated, either manua ly or automatically, said solenoid operates to move the door stop to inoperative position. The door, if open, therefore moves to closed position and the door stop itself becomes inoperative until intentionally reset. lt is preferably arranged that such resetting of the stop is et fectable only by means of a key.

It will be clear, that if all smoke doors of a building were fitted with such stops, it could be ensured that all such doors would be free to close on completion (or, conversely, breaking) of an electrical circuit or circuits, for example a fire alarm circuit.

The invention is further described with the aid of the accompanying explanatory drawings which illustrate more or less diagrammatically, and by way of example, two embodiments thereof.

In said drawings- FIG. 1 is a fragmentary perspective View of a swing door held in open position by a floor stop.

FIG. 2 is a vertical longitudinal section of the stop, drawn to an enlarged scale as compared with FIG. 1, in operative position, and

FIG. 3 is a view similar to that of FIG. 2 but showing the stop after actuation.

FIG. 4 is a longitudinal section of a wall catch in operative position, and

FIG. 5 is a View similar to that of FIG. 4 but showing the catch released.

Referring now to said drawings and first to FIGS. 1-3 inclusive, ltl denotes a swing door which is adapted to close an opening 11 and is biased towards closed position. The door till is adapted to be held in open position by means of a detent or stop 12 which is pivotally located in a housing 13 located in the floor x. Said pivotal detent 12 is biased to operative position (FIGS. 1 and 2) by a spring (not shown) but may be overriden by the door ill) in its opening movement. Said detent 12 projects sufficiently above the level of the floor x to en age the bottom of the door or a striker plate thereof and hold same open. Slidably displaceable in the housing 13 below said detent 12 is a block 15 influenced by a spring 14 and having an inclined surface 16. Said block in its forward position (FIG. 2) permits said detent 12 to become operative but when moved to its rearward position (PEG. 3) engages the underside of said detent 12 and pivots same to a position in which it is flush with the fioor surface and therefore can no longer function to hold back the door. The operative face 1? of the detent 1?. may be provided with a roller or other anti-friction device to facilitate its disengagement from the door. In rearward position of the block 15 a pawl 18 is arranged automatically to engage with a sear 19 formed in said block whereby its return movement is positively prevented. Said pawl 18 may be pivoted eccentrically so as to move by gravity to operative position, or to be springinfiucnced as by a spring 29. Said block 15 is associated with, or forms put of, the armature or plunger 21 of a solenoid 22 having terminals 23 for connecting same with an electric circuit which provides the current for operating same. A cut-out switch may be incorporated in the solenoid circuit and be operable by the plunger reaching the limit of its operative movement. An aperture 24 is provided in the casing 13 wherethrough a key may be entered to release the pawl 18 from the sear 19 of the block and thereby render the stop 12 operative.

The housing 13 is preferably of a dust proof nature.

In the modification illustrated in FIGS. 4 and 5, the housing 13 is adapted for location in a Wall 3/ and the detent consists of a catch member 31 pivoted on a pin 32 and the rear end whereof is operatively engaged with the plunger 21 of a solenoid 22. The forward end 33 of the catch 31 is adapted to be und-eiridden and be engaged by a catch member 34 secured to the back of the door 19. Alternatively said catch 32 may be arranged to engage the top of a door. The plunger 21 is formed with a scar l9 and a pawl 13 pivoted at 35 is arranged, under the influence of a spring 36, to engage said sear when said solenoid 22 is operated (FIG. 5) to retract the plunger 21 and move the catch to inoperative position. As before, said pawl 18 can only be relea ed from the sear 19 by means of a key inserted through an aperture 24 of the casing.

Door stops or catches according to my invention may be fitted, with obvious advantage, to swing or other selfclosing doors generally with the electro-magnetic release means connected with an electric circuit operated by a firealarm system or/ and by manually operated switch means.

What I claim as my invention and desire to secure by Letters Patent is:

1. A door stop for a swing or other self-closing door comprising a housing for being located flush within a floor or wall or other surface; a detent pivotally mounted within said housing and having a part capable of projecting from said housing for engaging a door; a member operably associated with said detent and slidaoly displaceable within said housing between a forward position in which said detent is in door engaging position and a rearward position in which said detent is in retracted door releasing position; a scar formed in said slidably displaceaole member; a spring influenced pawl for engaging said sear automatically when said member is in its rearward position and for locking same in such position; a solenoid for electro-rnagnetically displacing said member rearwardly; s sring means for moving said member forwards; and an aperture in said housing for introducing a key for releasing said pawl subsequent to operation of said solenoid.

2. A door stop, as claimed in claim 1, wherein said solenoid is adapted to be operated by electric current derived from an electric circuit forming part of a fire aiarm or other system whereby said detent is moved automaticaliy to inoperative position in the event the sys- 10 tern is actuated.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A DOOR STOP FOR A SWING OR OTHER SELF-CLOSING DOOR COMPRISING A HOUSING FOR BEING LOCATED FLUSH WITHIN A FLOOR OR WALL OR OTHER SURFACE; A DETENT PIVOTALLY MOUNTED WITHIN SAID HOUSING AND HAVING A PART CAPABLE OF PROJECTING FROM SAID HOUSING FOR ENGAGING A DOOR; A MEMBER OPERABLY ASSOCIATED WITH SAID DETENT AND SLIDABLY DISPLACEABLE WITHIN SAID HOUSING BETWEEN A FORWARD POSITION IN WHICH SAID DETENT IS IN DOOR ENGAGING POSITION AND A REARWARD POSITION IN WHICH SAID DETENT IS IN RETRACTED DOOR RELEASING POSITION; A SEAR FORMED IN SAID SLIDABLY DISPLACEMENT MEMBER; A SPRING INFLUENCED PAWL FOR ENGAGING SAID SEAR AUTOMATICALLY WHEN SAID MEMBER IS IN ITS REARWARD POSITION AND FOR LOCKING SAME IN SUCH POSITION; A SOLENOID FOR ELECTRO-MAGNETICALLY DISPLACING SAID MEMBER REARWARDLY; SPRING MEANS FOR MOVING SAID MEMBER FORWARDS; AND AN APERTURE IN SAID HOUSING FOR INTRODUCING A KEY FOR RELEASING SAID PAWL SUBSEQUENT TO OPERATION OF SAID SOLENOID. 